Sennheiser IE 900 Review

Sennheiser IE 900 Award

Design & Housing


If you have read our IE 300 review, the shape of the IEM will look familiar. The big difference being that it now isn’t plastic but precision milled aluminum.

The ribbed design also looks very nice and it feels great in hand. The air vent is nicely placed under the Sennheiser logo and it doesn’t disturb the looks. The left ear piece has the IE 900 lettering on the inside of the monitor and it has a black ring where the MMCX connecter is located. The right ear piece has a red ring and that’s it.

To me the IE 900 looks awesome, but that of course is something personal. To me the ribbed aluminum shows the high end level, while it for my wife looked like an unfinished prototype. So yeah, tastes are different, but I for one like the design.


Build Quality & Cable

A specialist team in Wedemark, Germany designs, engineers, and manufactures the IE 900 to the highest production standards. Its unique housings are precision milled from high-performance aluminum alloy to retain its pristine appearance for years to come. Precision cameras examine the transducer components closely during production, and completed transducers are tested before and after pairing. For optimal performance, the assembled left and right-side earphones are paired by hand to work together.

The build quality and finish of my set of IE 900 is perfect, there’s really nothing bad I can say about it, but it’s not surprising as they are manually assembled and checked. Important to see and note is that the IE 900 has a rib/ridge on the canal so the tip can be held in place. The nozzle is also sealed with a mesh so that dirt and wax can’t easily enter the IEMs. In fact the mesh logo can be found in the foam tips as well, as the foam mesh shares the same design. Sennheiser/Deutsche Gründlichkeit.

Sennheiser IE 900

The IE 900 comes with 3 sets of cables, as it should at this price level. Inside the box you’ll find an unbalanced cable with a 3.5mm connector and two balanced cables with 2.5mm and 4.4mm connectors. The cables are para-aramid-reinforced and they can withstand thousands of bending cycles. The MMCX-connectors allow you to use aftermarket cables, but more on that later.

The TPU coated cable is made from Oxygen-free Copper (OFC) and it features individual ear hooks to keep the IEMs in place. The cable is free of friction noise and I haven’t heard it pick up any interference from other devices.

Fit, Comfort and Isolation

The IE 900’s ear pieces are very small and they perfectly fit my ears. The canal is short and small in diameter, so it will fit all shapes of ears and stay perfectly in place. Of course tip selection here is critical – as it is for the sound -, but more on that later. The small units disappear in your ears and that’s something I like a lot. They’re even small enough to sleep with and wearing them for hours is comfy and painless.

One earpiece only weighs about 4 grams, so they’re not heavy in any way. They don’t want to fall out of your ears all the time, though the tip selection helps with that. The cable is very light as well, so the cable won’t be pulling on the earpieces either. And with the individually adjustable ear hooks, you can set the monitors just how you want, so they won’t bother you in any way.

Sennheiser IE 900

Isolation-wise these are closed monitors and they have a -26dB attenuation level. That means they isolate really well and they block out as good as all outside noise. That’s great for the sound quality and the musical experience on the go, but do pay attention when using these outside in traffic where cars and things can hit you.



For the testing we have used a mix of sources such as the Astell&Kern SP2000, the HiBy R8 and the HiFi-M8 V2 just to name a couple. The tips in use are the memory foam ones provided by Sennheiser, and the cable is balanced. More on tips and single ended use later in this article.

Sennheiser labels the IE 900 as an audiophile high end earphone for on the go and if you know how their high end headphone (the HD 800) sounds, you can get a clue of the direction the IE 900’s sound is going in. I have to say I like the HD800 as well as the HD 800 S, to give you an idea of my personal preference.

According to Sennheiser the IE 900 will give you “brilliant, natural high-end sound reproduction and reveals even the finest details in the music“. The broadband transducers, according to Sennheiser, prevent distortion and deliver a natural, balanced sound, to ensure audio transparency.

Let’s find out more!


Our impressions are based on the IE 900 in balanced mode, with a series of DAPs and other sources. For a comparison with the single ended cable, look for the topic a few paragraphs down.

The Sennheiser IE 900 is dead silent with all the sources I tested it with, it’s not picking up any noise from my sources and it has a pitch black background.

Sennheiser IE 900

The IE 900’s tuning is more to the neutral side but it’s not overly analytic in any way. The IE 900 mixes detail retrieval, precision and musicality perfectly, taking the best of everything. Body-wise the IE 900 is also more neutral, and it doesn’t enhance the bass or anything in any way. For me the amount of body is exactly what I expect and am used to from high end units. That means that it for some might be a little light, though it for me at this level is actually perfectly correct.

When first listening to the IE 900 you’ll be impressed with its excellent stereo imaging and L/R balance. Other highlights are the clarity, sound stage, note extension/decay and detail retrieval. The sound quality Sennheiser is getting from this new design is impressive. We of course already know what kind of detail the high end Sennheiser ear-and headphones can deliver, and it’s no different here.

The sound stage is both wide as well as deep, and the layering is very good. From bass to treble all the notes have excellent extension, and really good timbre, especially in the bass and treble, but also in the mids (to a maybe lesser extent). The IE 900 is spacious and airy, but never exaggerates. As a result you get a realistic and natural perception of the music, and that with excellent clarity from top to bottom.

The separation is good, it’s not as precise and impressive as in multiple BA IEMs but I personally never felt it to be lacking. To me the IE 900 is fairly balanced though there’s an emphasis on the upper mids and therefor you – depending on the music listened to – could find the lower and mid mids more to the back. What the IE 900 to me certainly is, is more vocal forward.

The article continues on Page Three. Click here or use the jumps below.

Page 1: Sennheiser, Intro, IE900, Specifications, Box & Accessories

Page 3: Sound Part 2, Single Ended, Tips, Sources

Page 4: Cables, Competition, Conclusion, Award


Lieven is living in Europe and he's the leader of the gang. He's running Headfonia as a side project next to his full time day job in Digital Marketing & Consultancy. He's a big fan of tube amps and custom inear monitors and has published hundreds of product reviews over the years.


  • Reply May 11, 2021


    Can you compare it to the IE800(s)?

  • Reply May 11, 2021


    About Xelento, I had it but finally sold it because I’m more an headphone guy : the foam tips is not the better match with Xelento, in fact the olive tips (with the bigger size) provided with Xelento is what really reveal the Xelento, with these tips the sound coming from Xelento is impressively out of your head, it is really headphone like and an experience to try.

    You can easily find Xelento less than 1000eur (amazon, etc)

  • Reply May 11, 2021

    Daniel afred

    pls can you tell me the differences between the IE900 and the Audeze euclid

  • Reply May 11, 2021

    Daniel alfred

    Good review by the way

  • Reply May 11, 2021


    Thanks for the great review. I’m very interest to read how Senn IE900 compares against Final Audio A8000.

    • Reply May 12, 2021


      How does the ie900 compair to the JH Roxanne?

  • Reply May 12, 2021


    Well done senheizer

  • Reply May 14, 2021

    Paulo Lobao


    Compared to CA Dorado2020…?

  • Reply May 21, 2021

    da berg

    It is a shame in todays age where people want wired headphones of high quality for their phones this did not leave an option to purchase with a mic.

    If it had a mic I would totally buy it

    • Reply August 1, 2021


      You buy a high quality wired headphone to play with DAP! Not a phone. lol

  • Reply May 23, 2021

    Paradorn Suksingha

    Please pairing with Shanling M8 and share experience. Thanks.

    • Reply May 23, 2021


      I don’t have the Shanling DAP here, sorry

  • Reply July 28, 2021


    The most obvious difference is the extension of the high frequency part. The high frequency of ie900 is bright and natural. In other aspects, ie900 has a very good sense of hierarchy and better analytical power. It sounds like ie800s has 2K image quality and ie900 has 4K image quality

  • Reply September 5, 2021


    Can you share how they sound with fiio m15?

    • Reply September 7, 2021


      I don’t have the M15 with me, sorry.

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